What I do: open a program like Paint (comes with Windows) or Irfanview (free download) and ctlr-V to paste the picture into it.
The clipboard isn't a program you can run. It's just a place to store something.
The original clipboard viewer program from Microsoft doesn't exist anymore, although you can still copy it from your Windows XP computer. https://www.majorgeeks.com/files/details/free_clipboard_viewer.html is a third party equivalent. Personally, I don't need it.
After a screen capture or print screen command, how do I navigate to the clipboard on my Windows 10 computer